You can only unlock the chapter using a special code that we will send you via the Viber app. Receiving a message is free of charge and with no obligations.
My phone number:
Get a code
In compliance with the law, persons under the age of 15 can enter their phone number only in the presence of a parent or guardian.
4-character (Viber) code:
Check the received code
The page will be refreshed automatically in a few seconds.
On Monday, the cost of a concert ticket is . On Tuesday, the cost of a ticket for the same concert is more than the cost on Monday. Jack buys 4 tickets on Monday and 5 tickets on Tuesday. Jack pays in total. Work out the value of .
To ensure the proper functioning of the website, OpenProf uses cookies that do not store personal data. By continuing to use the website, you agree to cookies. Tell me more »